Plants are capable of doing far more things than just being green and sitting there.

Forests can communicate between groves of individual trees; they find ways to ecologcially claim and defend territory (allelopathy); plants develop relationships for mutual benefit with fungi (mycorrhizalnetworks); and they have recently been observed to channel light into their root tips allowing for growth in a directed fashion.

These are just a few examples of the genius seen in green plants. While they may not have brains consisting of neurons, plants still operate 'intelligently'. A person would probably have also learned something useful, efficient, and important for survival if you were the result of nearly 1 billion years of evolution yourself.